The present invention relates to an optical device having a waveguide provided on a substrate and, more specifically, to an optical device able to connect the waveguide on the substrate to an external optical transmission path, and also an optical connector assembly and optical connection method for connecting a waveguide on a substrate to an external optical transmission path.
There is growing demand for optical interconnect technologies with faster speeds and reduced power consumption. In order to realize both faster speeds and reduced power consumption, photoelectric conversion units with faster speeds and reduced power consumption are being developed along with optical multichip modules (optical MCMs) in which optical signal input/output units have been provided near semiconductor circuit chips on a mounting substrate.
The optical interconnections in these optical MCMs have to be connected to an external optical interconnection circuit via optical transmission paths such as optic fibers with low loss. In the prior art, a technique has been used in which optic fibers are connected to waveguides on a substrate via optical connectors on the side surface of the optical MCM substrate. FIGS. 18(A) and 18(B) are diagrams showing an optical MCM and optic fiber connecting structure of the prior art. FIG. 18(A) is a side view, and FIG. 18(B) is a top view.
In the optical MCM 500 shown in FIGS. 18(A) and 18(B), optical waveguide layers 510 is formed on the surface of an optical substrate 502 from the end of the board to a location near a mounted semiconductor chip 520. A 45° mirror 512 is formed in the waveguide layer 510 to deflect light passing through the core upwards or deflect light from above into the core. A vertical cavity surface emitting laser (VCSEL) 528 is provided on the transmitting end, and a photodiode (PD) 526 is provided on the receiving end in a position corresponding to a mirror 512 in the waveguide layers 510, and these components are fixed using an underfill 516.
A transimpedance amplifier/limiting amplifier (TIA/LIA) 522 for amplifying electrical signals from the PD 526, and a laser diode driver (LDD) 524 for driving the VCSEL 528 are provided on an inorganic substrate 502. The TIA/LIA 522, LDD 524, PD 526 and VCSEL 528 are connected by way of vias 514 to electrical wiring 506 formed in the organic substrate 502. An optical connector 540 is provided on an end surface of the optical substrate 502, and a fiber ribbon 530 and waveguide layer 510 are connected via the optical connector 540.
Another optical interconnector technology related to optic fibers and waveguides has been disclosed in Laid-open Patent Publication No. 2004-191565. An optical path conversion connector is disclosed which includes bundled optic fibers and waveguides or photoelectric conversion elements arranged one-dimensionally or two-dimensionally, and establishes an optical connection with an external component with a positioned member.